Quantitative 3D ultrasound imaging using an automated image tracking technique

A new method for acquiring dimensionally accurate 3D ultrasound data from multiple 2D image planes is proposed and tested. This is based on the use of a modified linear phased array comprising a central 'Imaging' array that acquires multiple 2D slices as the transducer is passed through the tissue of interest. Small, perpendicularly oriented, 'Tracking arrays' are integrally mounted on each end of the Imaging transducer. As the transducer is translated in an elevational direction, the images obtained by the Tracking arrays remain largely coplanar. The motion between successive Tracking images is determined using image matching based on the Minimum Sum of Absolute Differences (MSAD) criterion. Initial testing of a prototype 8 MHz array indicates that linear dimensional accuracy of approximately 5% is attainable. The applicability of the approach towards a low cost, rapid screening method for detecting stenosis in the carotid artery has been tested. Accurate estimates of stenosis, referenced to data acquired by Magnetic Resonance Angiography (MRA) or X-Ray angiography, were obtained in an average of 12 minutes as compared to approximately 45-50 minutes for conventional full duplex 2D/Color ultrasound scans.